Cheat Mode
At the rewards screen, press square to access the cheat menu. You can unlock these cheats by playing the game:

Big Melon - Win the European Champions Cup. Players have giant heads.
Crazy Ball - Win the EFA Trophy. Press square after you pass the ball and it will change direction.
Stay N Play - Win the European Championships. The ball will stay inside the lines.
They All Fall Down - Win the Copa America. Players will fall if they keep the ball to long.
Eye Catcher - Win the Gold Cup. The ball will be very big.

Unlock Bonus Tournaments
Win the AFC to unlock the Asians Nations Cup
Win the CONCEBOL to unlock the Gold Cup
Win the CONCACAF to unlock Copa America
Win the UEFA to unlock the European Championships (Euro 2004)
Complete all rewards except the last locked one to unlock the FIFA Confederations Cup.